Turbo-blower.



PATENTED MAY 14, 1907.

H. HOLZWARTH. TURBO BLOWER.

' APPLICATION FILED MAY 26. 1906.

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' HLHOLZWARTH.

TURBO BLOWER.

APPLICATION FILED MAY 26. 1906.

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UNITED STATES PATENT OFFICE.

HANS HOLZWARTH, or HAMILTON, oriio, ASSIGNOR TO THE HOOVEN, OWEN,

RENTSOI-ILER COMPANY, OF HAMILTON, OHIO.

TURBO-BLOWER.

Specification of Letters Patent.

Patented May 14, 1907.

Application filed May 26,1905. Serial No. 262,341.

To (LZZ whom, it may concern:

Be it known that 1, HANS HOLZWARTH, a citizen of Germany, residing in Hamilton, Butler county, Ohio, (post-office address Hamilton, Ohio,) have invented certain new and useful Improvements in Turbo-Blowers,

' of which the following is a specification.

This invention relates to that class of high speed blowers adapted for direct connection to high speed rotary prime movers, such for instance, as steam turbines, the construction of the blower being based on the principle of the axial flow turbine.

The invention will be readily understood from the following description taken in connection with the accompanyingdrawing in which:

Figure 1 is a front elevation, part vertical section, of a turbo blower exemplifying my invention: Fig. 2, a diagram illustrating a set of the stationary and running blades: Fig. 3, a face view of a portion of one of the running wheels: and Fig. 4, a diametrical section of a portion of one of the running wheels.

In the drawings :1, indicates the bed for the blower, which bed is to be preferably prolonged to carry also the prime mover: 2, the general hollow blower structure mounted thereon: 3, the air inlet to the interior of the blower: 4, a pair of discharge branches from the interior of the blower: 5, the compressed air outlet from the blower, the same representing a converging of the two discharge branches: 6, bearings for the blower shaft: 7, a horizontal bolted joint, at the level of the axis of the bearings, connecting the upper portion of the hollow blower structure with the base portion thereof, the general hollow portion of the blower structure being disposed between the two bearings: 8, a vertical bolted joint connecting the two side portions of the hollow blower structure, the plane of this joint being at right angles to the axis of the bearings: 9, horizontal joints connecting the two discharge branches 4 with the tee-piece carrying them to the common outlet 5: 10, the blower shaft, journaled in the bearings and extending axially through the turbine chamber of the blower structure:

11, a coupling on this shaft through which 13, 14, 15 and 16, a set of running turbine wheels secured to the turbine shaft at one side of the center of length of the turbine chamber, the eripheries of these wheels being armed wit turbine blades whose outer extremities run contiguous to thewall of the turbine chamberinclosing them: 17, 18, 19, 20 and 21, a set of stationary turbine disks, alternating with the running wheels referred to, these disks having their peripheries secured in the wall of the turbine chamber and having their inner bores fairly fitting the running structure within them, the outer portions of these disks being provided with turbine blades, the adjacent faces of the stationary disks and running wheels being preferably as close to each other as proper running will permit: 22, the blades of the running wheels: and 23, a second set of stationary disks and running wheels constituting a duplicate of the set before mentioned, this second set being arranged on that side of the longitudinal center of the turbine chamber opposite the first mentioned set, the two sets being symmetrically arranged so that the air inlet to the turbine chamber leads between two stationary disks.

So far as mere mechanical construction of the disks and running wheels is concerned, as regards the manner of-providing them with blades and the manner in securing them to the shaft and within the casing, nothing specially need be said as approved steam turbine construction may be followed. For the sake of brevity, I will call the stationary turbine disks the disks, and I will call the running turbine wheels the runners.

Before taking up the principles of action of the blower, certain structural features may well be referred to. The horizontal joint 7 permits the entire upper portion of the casing to be removed, thus exposing all of the turbine elements. The joints 7 and 8 per mit a single one of the upper portions of the main casing to be removed. This system of jointing the casing is manifestly advantageous in original construction and in subsequent overhauling. v

The free air enters the blower chamber be tween the two sets of turbine elements and the body of air diverges, the two bodies of air becoming compressed in passing the turbine elements and joining again before reaching the common outlet. The air going to one set of the turbine elements is compressed to a certain extent by the first runner, and still more by the next runner and so on, the runners of the set accumulating their effects;

Giving consideration to a single set of the turbine elements, the air flows in axial direction through the first disk, the dill'user, then through the alternating runners and disks beyond the diffuser, the air at final compression leaving the last disk, which is the e'l'l'user. The capacity of the arrangement, as to pressure and volume, can be varied according to the influx and el'l'lux angles of the blades and the area of the passages between the blades. These angles must be in such harmony that the air follows the blades with the least possi ble resistance. It will be readily under stood. that it is desirable to have the runners .rotate at the highest practicable speed in rows, and in which 17 indicates the diffuser and 21' the efi'userz-As the first runner 13 moves at the highest practicable speed it is important that the air flow to this runner at a proportionate velocity. The acceleration of the air in the first disk or di'l'l'user 17, is compensated for by an expansion of the air below the pressure of reception. The result is that the first disk or di'l'luser is exposed to an axial air pressure in the direction of the air flow. In the first runner, 1.3, the air is taken from the diffuser with a certain relative velocity. The blades of this runner must be so curved. that when leaving the blades the air will be compressed to such degree that not only the expansion in the diffuser is compensated for but also a certain positive compression is attained. This is accomplished by making the advance faces of the runner-blades convex with the eli'lux angle of the blades of the runner less than the influx angle, tl e angle being referred. to a plane at right angles to the axis of the turbjine. The result is that the first runner effects a positive compression of the air and that this runner is exposed. to an axial air pressure in a direction against that of the air flow. The blades of the second disk take up the air from the first runner at a certain velocity. The purpose of these blades is to guide the air in such a way that the second runner can take up the air again with the least possible resistance. When laying out several di'll'erent angle diagrams it will be readily found that it is advisable to curve the blades of the second disk so that the efflux velocity is greater than. the influx velocity. This results in an acceleration of the air within the second disk with a corresponding expansion, so that the second disk is also exposed to an axial air pressure in the direction disks and runners in. series it is possible ll] compress the air with. a total eilieienev of about seventy per cent up to any prarairal limits. Upon leaving the blades of ihe lasl runner the air is taken up by the blades ol the last disk, 2i, the ei'l'user. Iln this elluser the velocity of the air is reduced to a small amount by properly curving the blades and by materially increasing the radial lengi h ol the blades. Thus a further compression takes place in the ell'user, eompensaiing for the retardation of the air flow. While all of the previous disks are exposed to an axial thrust in the direction of the air flow, the final disk or eil'user is exposed. to an axial thrust in the opposite dire 'w'tion. The radial length of the blades of the (.lisks and runners prior to the efi'user may be gradually de creased progressively toward the eli'user in general proportion to the reduction of volume by compression.

It will be readily understood that by changing the influx and efflux angles of the blades the axial thrusts can be modified, bul in any case the thrust upon the runners will generally be greater than the thrusts upon the disks, and generally so great that they cannot be satisfactorily cared for by means of thrust-bearings. In my cmistruetion ilie symmetrical disposition of two sets of lurbi'ne elements manifestly brings about a compensation of the thrusts upon the runners. The air enters between the two sets of eh ments and the divisions of the air heroine equally compressed, the two divisions of equally compressed air later joinii'ig for discharge. The objection that this double arrangement requires nearly double the longl h of a single turbo blower is not fully correct. as a single turbo blowerwould require a dummy piston. to compensate for the thrusts, an arrangemcnt itself taking up a very considerable space and being attended. by the (llszldvantage that the leakage losses at the periph cry of the piston decreases materially the elliciency of the blower. Furthermore, a single turbo blower requires, for equal caparitv, blades having approximately double the ra dial dimension of those of a double blower. The windage resistance of the runners. which constitutes about ten or lifteen per cent of the total losses, is pro iortionaie lo the third power of the radial length of the blades. The total windage loss of a double blower is therefore four times smaller than that of a single blower. It is therefore seen that there are distinct advantages in favor of the double turbo blower with multiple compression.

, Referring to Fig. 2 it is to be observed that considering a single runner blade, the ad vance face of the blade is convex and that the face progressively retreats from. a line perpendicular to the plane of revolution, the anof the air flow. By thus arranging several 1 gle of retreat from. such line being at some degree at the influx edge of the face and a greater degree at the effluX edge of the face.

I claim as my invention A turbo blower comprising a casing provided with an air inlet and an air outlet, a shaft mounted therein, a series of disks mounted in the casing concentric with the shaft and provided with curved blades, a series of runners fast on the shaft and alternating with the disks and provided with curved blades, the joint series of disks and runners beginning with and ending with a disk, the advance face of each runner-blade being con- 

